An air bag for restraining an occupant of a vehicle is inflated upon the occurrence of a vehicle collision. Inflation fluid is directed to flow from a source of inflation fluid into the air bag to inflate the air bag. The inflation fluid inflates the air bag from a stored condition to an inflated condition in which the air bag extends into the vehicle occupant compartment. When the air bag is inflated into the vehicle occupant compartment, it restrains an occupant of the vehicle from forcefully striking parts of the vehicle.
The air bag is stored in an air bag module which is mounted in the vehicle. In addition to the air bag, the module contains an inflator and may contain a diffuser. The inflator comprises the source of inflation fluid. The diffuser, if included, helps to direct the inflation fluid from the inflator into the air bag when the inflator is actuated. Typically, an air bag module also includes a canister which contains the air bag, the inflator and the diffuser. The canister is mounted in the part of the vehicle in which the air bag is to be located, such as the instrument panel of the vehicle, and is covered by a deployment door which opens upon inflation of the air bag.